1. Field of the Invention
The present invention relates to the field of switching power supplies.
2. Prior Art
Switching DC-to-DC converters are well known in the prior art. Such converters include multi-phase converters wherein two or more switching converter stages deliver power to a common output terminal. Such converters normally operate in an interleaved manner, reducing the ripple on both the input and output of the converter. This, in turn, reduces the amount of filter capacitance needed on both the input and the output, which can reduce the overall cost and board space required for the converter. An example of a multi-phase converter is given in U.S. Pat. No. 5,870,296.
The present invention has among its various objects the achievement of multi-phase converters with a faster time response to sudden increases in the load on the converter output.
Multi-phase switching converters and methods that provide fast response and low ripple on the converter inputs and outputs. The converters include multiple converter stages that are normally operated in sequence into a common load. However upon sensing that operation of one of the converter stages does not bring the converter back into regulation, multiple converter stages are operated until regulation is reestablished, after which the converter stages are operated in sequence again. In the embodiment disclosed, upon sensing that operation of one of the converter stages does not bring the converter back into regulation, all converter stages are operated until regulation is reestablished, after which the converter stages are operated in sequence again starting with the stage with the lowest inductor current. Various embodiments and a specific implementation are disclosed.